PTF 3207A Frequently Asked Questions (FAQs)
The following FAQs are provided to assist in successful operation / troubleshooting of the ptf 3207A GNS Family of Time and Frequency Receivers.
There is a problem with the communications
Before connecting to the Telnet interface it is necessary to set up the unit IP address and Net mask.
If these were set automatically by DHCP, the current values of these can be determined from the front panel IP status screen selection (press MAIN and then scroll down to IPv4 data and press ENTER). Static IP address/net mask can be set by using the front panel menu (press MENU and then scroll down to the IP settings)
Alternatively the values can be set by using the Serial Interface and using the IP setup commands on the menu.
Typical settings would be;
IP Address 192.168.0.19
Net mask 255.255.255.0
Once the IP address/Net mask has been set up and the unit is connected to a network (or directly to a computer using an Ethernet crossover cable) a hyper-terminal (or other telnet interface program) session can be set up using the unit’s network IP address.
To login to the telnet interface a user name and password must be provided. The default user name is admin (lower case) and the default password is ptf_pwd
Before connecting to the Telnet interface it is necessary to set up the unit IP address and Net mask.
If these were set automatically by DHCP, the current values of these can be determined from the front panel IP status screen selection (press MAIN and then scroll down to IPv4 data and press ENTER). Static IP address/net mask can be set by using the front panel menu (press MENU and then scroll down to the IP settings)
Alternatively the values can be set by using the Serial Interface and using the IP setup commands on the menu.
Typical settings would be;
IP Address 192.168.0.19
Net mask 255.255.255.0
Once the IP address/Net mask has been set up and the unit is connected to a network (or directly to a computer using an Ethernet crossover cable) a hyper-terminal (or other telnet interface program) session can be set up using the unit’s network IP address.
To login to the telnet interface a user name and password must be provided. The default user name is admin (lower case) and the default password is ptf_pwd
Before connecting to the HTTP interface it is necessary to set up the unit IP address and Net mask.
If these were set automatically by DHCP, the current values of these can be determined from the front panel IP status screen selection (press MAIN and then scroll down to IPv4 data and press ENTER). Static IP address/net mask can be set by using the front panel menu (press MENU and then scroll down to the IP settings)
Alternatively the values can be set by using the Serial Interface and using the IP setup commands on the menu.
Typical settings would be;
IP Address 192.168.0.19
Net mask 255.255.255.0
Once the IP address/Net mask has been set up and the unit is connected to a network (or directly to a computer using an Ethernet crossover cable) communications can be established using a standard web browser (e.g. Internet Explorer) and typing the address into the browser bar e.g.:
http://192.168.0.18/
To login to the web interface a user name and password must be provided. The default user name is ModuleA and the default password is ptf_pwd
These traps will be received by the SNMP manager on the Trap Ringer Console. Traps are enabled or disabled by the SNMP Traps command on the menu.
Before connecting to the SNMP interface it is necessary to set up both the unit IP address and Net mask, and also the SNMP Manager address to which traps are to be sent. These can be set by using the Serial Interface and using the menu commands.
Alternatively, if the unit is connected to a network with a DHCP (Dynamic Host Communications Protocol) server, the unit can be set to DHCP mode and the unit will automatically acquire a network address from the DHCP server. The current values of these can be determined from the front panel IP status screen selection (press MAIN and then scroll down to IPv4 data and press ENTER).
Once the IP address/Net mask has been set up and the unit is connected to a network (or directly to a computer using an Ethernet crossover cable) communications can be established using a standard SNMP manager software package.
The SNMP configuration file is shown below:
# snmpd.conf file
dlmod ptfSnmpPlugin /lib/ptfSnmpPlugin.so
#create users
createUser ptfOne MD5 “okayuser” DES
#access control – make them all read/write
rwuser ptfOne
rocommunity public
rwcommunity private
# First, map the community name (COMMUNITY) into a security name
#sec.name source community
com2sec local default private
com2sec local default public
com2sec remote default public
# Map the security names into group names:
#sec.model sec.name
group MyROSystem v1 local
group MyROSystem v2c local
group MyROSystem usm local
group MyROGroup v1 remote
group MyROGroup v2c remote
group MyROGroup usm remote
group MyRWGroup v1 readwrite
group MyRWGroup v2c readwrite
group MyRWGroup usm readwrite
# Create a view to let the groups have rights to:
#incl/excl subtree mask
view all included .1 80
view system included .iso.org.dod.internet.mgmt.mib-2.system
# Grant the 2 groups access to the 1 view with different
# write permissions:
#context sec.model sec.level match read write notif
access MyROSystem “” any noauth exact system none none
access MyROGroup “” any noauth exact all none none
access MyRWGroup “” any noauth exact all all none
# —————————————————————
# List of the users (v3) that have access to the configuration system
rwuser initial
createUser initial MD5 12345678 DES
#################################################################
# Sending traps to SNMP Manager
#
#trapv1
trapsink 192.168.0.14 #note, set by system.
#trapv2
#trap2sink 192.168.0.14 #note, set by system.
#trapv3
#informsink 192.168.0.14 #note, set by system.
#snmptrap -v 1 -c public 192.168.0.14 “” “” 1 0 “”
#snmptrap -v 1 -c public 192.168.0.14 “” “” 6 99 “”
###############################################################################
# System contact information
#
# ** NOTE **
# setting the value of these objects here makes these objects READ-ONLY
# (regardless of any access control settings). Any attempt to set the
# value of an object whose value is given here will fail with an error
# status of notWritable.
#syslocation Wakefield, Massachusetts (configure /etc/snmp/snmpd.local.conf)
#syscontact David Briggs <root@localhost>(configure /etc/snmp/snmpd.local.conf)
</root@localhost>
Access via the front panel keypad can be protected by use of a four number “PIN”. A special “hidden” menu command, KEYPAD-PIN is available to select a PIN of your choice. There is also an equivalent keypad menu entry item, accessible if hidden commands are visible. If this entry is set to 0000 the pin is not active and access to the setup menus is granted just by pressing the “MENU” key. Any other number up to 9999 will activate the PIN and before any menu items can be changed the PIN must be entered. The PIN will remain active during an editing session. Once an editing session is complete, or at any time during the editing process, pressing the “MENU” key will reset access and to re-enter edit mode the PIN will need to be re-entered.
The unit does not seem to initialize
The fault LED is a tri-color LED . When the unit is first powered ON, the Fault LED should momentarily cycle through the RED, ORANGE and GREEN states. After initial memory checks have been successfully completed the Fault LED should turn to flashing ORANGE while further initialization of the unit takes place. If the fault LED flashes RED, it is an indication that the selected input source is in ALARM state. If the Fault LED remains solid RED, this indicates a catastrophic failure in the unit, and the unit should be returned to the factory for repair.
The Fault LED will remain ORANGE during preliminary initialization of the unit, before moving on to initialization of the internal GPS module, when the Fault LED will remain on but the GREEN Lock LED will begin to flash.
Once the GNS “engine” has acquired sufficient satellites (4 if self survey is configured, or 1 if fixed mode is configured) the Orange Fault LED will extinguish, and the Green Lock LED will continue to flash until the init has locked the internal oscilattor
Also, after successful initialization, the Fault LED will illuminate ORANGE and the Lock LED will be OFF if the unit goes into the “holdover” mode.
In order to determine whether the unit has initialized, the serial or Telnet ports can be used to more fully determine unit status.
Following initialization of the internal GPS engine, the fault LED will extinguish, but the Lock LED will continue to flash (unless the unit contains an internal Rubidium atomic clock, in which case the Lock LED will immediately illuminate). This indicates that the unit has moved on to the next phase of initialization, which is to lock the internal oscillator to the incoming GPS signal, using the Phase Lock Loop “fast” mode. Dependent upon oscillator type, and how many “in range” samples have been preset, and also how many GPS satellites are in view (the unit will not take measurements while there are insufficient satellites to provide a good incoming GPS signal) this can take a varying amount of time.
The unit undertakes continuous self checks, one of which is to verify that the configured (selected) input source is present. If an input source that is not present is selected (e.g. the input source is selected as Time Code, but no Time Code input is present), the unit will indicate a fault by flashing the Fault LED between RED and GREEN, until the input fault is corrected.
During Operation
This is a normal mode of operation when the unit goes into the “holdover” mode. Holdover is caused by loss of a reliable input signal, usually due to insufficient viewable satellites (or if the Ext In 1 mode is selected, loss of input 1PPS signal), or possibly a problem with the antenna cable. The unit will continue to provide a good output, with an accuracy dependent upon the type of internal oscillator fitted and the length of time the unit remains in holdover. Once view of satellites is restored, the unit will revert to normal operation. The green Lock LED will not illuminate until the unit has taken sufficient good samples to recover the phase lock loop.
The unit undertakes continuous self checks, one of which is to verify that the configured (selected) input source is present. If an input source that is not present is selected (e.g. the input source is selected as Time Code, but no Time Code input is present), the unit will indicate a fault by flashing the Fault LED between RED and GREEN, until the input fault is corrected.
The time display is incorrect.
The modes of time output display are;
Local Time
GNS
UTC
GPS time display is simply UTC with a difference of the number of leap seconds since 24:00:00 on January 5, 1980 (the commencement of GPS time), which in 2006 are currently 17 leap seconds. Therefore GPS time will be ahead of UTC time by 17 seconds.
Local time is dependent upon the unit time settings. To display a correct local time, the local time offset from UTC must be entered (menu command T-OFFSET). The local time offset is the time zone difference between local time and GPS. For US Eastern Time the value to be entered is –50 (which represents –5 hours behind UTC). The next parameter is daylight savings time (menu commands DST and DST-TYPE). Currently this is only implemented for the USA and the UK. For other locations, the time offset must be adjusted accordingly, dependent on the time of year.
If the IRIG B time code output is being used from the rear of the unit, the time output will be the same as the time display settings.
The unit was working, but now I have moved location and it will not initialize anymore.
In order to provide accurate time, the unit must first be set to, or acquire, accurate position. For first time initialization, this is usually done by using the “survey’ mode (menu command RCVR1-MODE) so that the unit automatically acquires accurate position during initialization. Survey mode requires a minimum of 4 satellites in view to complete the initialization. After first time initialization, position will be remembered and the unit can be set to ‘fixed’ position mode which will enable a faster initialization as only one satellite needs to be tracked to set accurate time.
If the unit is then moved it is necessary to re-survey the position, as at a minimum there will be an inaccuracy in the time signal, and in the worst case, where the unit is moved many kilometers, the unit will not be able to locate the expected satellites and will not complete the GNS lock initialization.
I am using the external 1PPS input as my source, but the unit will not initialize, the fault LED stays ON and the Lock LED continuously flashes.
The normal default mode for the unit has GPS selected as the source for the 1PPS input (menu command 1PPS-SRCE). In this mode there are three phases of initialization;
During this phase, the unit is setting the internal ports, establishing the Ethernet port and serial port communications and several other set up functions to set the basic functionality of the unit.
The Power and Fault LED’s will be ON and the Lock LED will be off during this phase.
During this second phase initialization the internal GPS engine will acquire satellites and establish an accurate position needed for accurate time. This phase can take a variable amount of time dependent upon satellite visibility.
During this phase the Power and Fault LED’s will be ON, ad the Lock LED will be flashing.
Once the internal GNS engine has acquired satellites and locked, the unit will move onto the third stage of initialization, which is to lock the unit 1PPS output to the incoming GNS 1PPS signal. Depending on the type of oscillator fitted (TCXO or OCXO or Rubidium) this can again take a variable amount of time.
During this phase, the Lock LED will be flashing, the Power LED will be ON, and the Fault LED will be off.
If the unit is to be used with an External PPS signal source(e.g. a cesium standard) as the reference instead of GPS, it is necessary to set the unit into the correct mode (menu command 1PPS-SRCE). Available options are:
Rcvr-1
Rcvr-2
ExtTCAM
ExtTCDC
ExtPPS
ExtRF
